Alcryst was born as the second Prince of Brodia, eight years after Diamant. So he was probably a surprise baby, awww. ♥ Buuut despite being loved by his family, a bunch of people around the castle and some nobles were always comparing him to Diamant, saying Diamant could do everything better. Instead of getting jealous and butthurt and pulling a Jan Brady, though, Alcryst just decided they were right. He didn't blame his big brother for being amazing, how could he? So the poor boy grew up in Diamant's shadow.
In the game, he met Alear and Prince Alfred at the border of Brodia and shot at them. O_o;;; He thought they were thieves, and he'd never seen Alear before and probably didn't remember Alfred! Then when he realized his mistake he did the biggest, most EPIC apology ever:
But luckily all was forgiven, awwwww. They fought Princess Hortensia at the bridge and then they went back to Brodia where they fought off Princess Ivy. But then Alcryst's father King Morion went to meet King Hyacinth of Elusia on the battlefield (even though Diamant told him it was a trap!! Dammit Morion, you're such a good daddy, why do you have to be so prideful?. He almost won, but then (SPOILER!!!) Hyacinth killed him and brought him back as a Corrupted. ;_;
Poor Alcryst and Diamant were forced to put down their father, and later Alcryst got MAD at Ivy for playing a part in his dad's death. (It totally wasn't her fault, Ivy's a good girl, but ALCRYST HAD THE RIGHT TO BE UPSET, AND DIAMANT WAS KINDA MEAN TO HIM!! Grrrr. Issok, though, Diamant is still cool and loves his brother.) Then Alcryst kinda stopped being in cutscenes cause the younger royals aren't main characters. :( That totally sucks! Fates had all the royals in cutscenes!
But Alcryst kept fighting alongside Alear, brought down the evil Sombron, and either married Alear with the Pact Ring or went back to Brodia to support Diamant. Unfortunately he doesn't have plot armor so if you let him die he stays dead. ;_; DON'T LET HIM DIE!!